The candidate is an Assistant Professor of Medicine at the University of Illinois at Chicago (UIC) where she earned her MPH in Public Health/Epidemiology/Biostatistics. Her long-term goal is to establish an independent program for health services research in rheumatology, with a focus on how race/ethnicity, gender, and cultural factors influence health care utilization. The candidate has outstanding institutional and departmental support for her research endeavors, with substantial Department commitment to health services research and strong connections to the School of Public Health. If funded, the candidate plans to focus on 3 distinct areas: publishing original research in peer review journals, improving teaching, and developing practical applications. She will continue to submit grant applications to support these ideas. In patients with severe knee osteoarthritis (CA), total knee replacement (TKR) relieves chronic pain, restores lost function, and is cost- effective. TKR is underutilized, and utilization varies widely by race/ethnicity and gender. The sixth 2010 Healthy People arthritis-related objective to eliminate racial disparities in the rate of total knee replacements underscores both the existence of this variation and the need to reduce it. In order to eliminate racial disparity, we must first understand the underlying reasons for this variation. Based on our pilot studies, we believe perceived social support is a significant patient-related factor in TKR decision-making that varies between groups and may contribute to different TKR utilization patterns. We therefore hypothesize that perceived social support may be critical in understanding race/ethnicity and gender differences in TKR rates. Specifically, 1) perceptions of social support differ significantly by race/ethnicity and gender and result in different TKR decisions; 2) race/ethnicity and gender differences will be significantly reduced when perceived social support is considered, implying that perceived social support mediates or accounts for observed gender and race differences, which in turn affects the TKR acceptance rates; 3) prior to surgery, minorities and women require higher levels of perceived social support in order to choose TKR. We propose to test this hypothesis in a prospective longitudinal study of 320 subjects with severe knee CA who are recommended TKR. We will measure perceived, actual, and structural social support, other sociodemographic characteristics, disease severity, perceived health, and patient perceptions of costs and benefits of TKR. Results will be used to generate and test an intervention that promotes appropriate earlier clinical treatment for individuals. Characterization of these differences will also shed important new light on patient decision making, enabling health care providers to help patients improve function and quality of life.